Word processor which does not activate a display unit to indicate the result of the spelling verification when the number of characters of an input word does not exceed a predetermined number

ABSTRACT

A word processor having a spelling verification function which is achieved in more efficient manner through the use of an independent control unit. The capacity of a text buffer memory can be reduced, as the entered text is verified word by word, and each verified word is stored as a code in the memory to economize on the capacity of the memory.

This application is a division, of application Ser. No. 08/296,978 filedAug. 26, 1994, now abandoned, which is a continuation of applicationSer. No. 07/959,477, filed Oct. 9, 1992, now abandoned, which is acontinuation of application Ser. No. 07/430,953, filed Nov. 1, 1989, nowabandoned, which is a continuation of application Ser. No. 06/798,322,filed Nov. 15, 1985, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a word processor, and more particularlyto a word processor with a spelling verification function for the wordsentered by keyboard.

2. Description of the Prior Art

In recent years, word processors have become available in compacter formand are attaining wider. So-called electronic typewriters have shownremarkable progress with new functions supported by electronictechnology, while maintaining the traditional functions of a typewriter.One of such new functions is spelling verification which provides theadvantage of correcting the text as it is entered as each entered wordis verified by a dictionary in the typewriter and the operator isimmediately informed of any misspelling.

However this function requires large memory for the dictionary, thusleading to a higher cost and larger dimension typewriter, and hasrequires a certain time for processing.

Also a dictionary containing only ordinary words is unable to handleproper nouns such as human 1names, and special technical texts, and theverification errors caused in these cases are rather inconvenient forthe operator.

SUMMARY OF THE INVENTION

In consideration of the foregoing, an object of the present invention isto avoid such drawbacks and to provide a compact and inexpensive wordprocessor with improved performance, in which the capacity of the textmemory can be significantly reduced by effective utilization of adictionary containing ordinary words only.

Another object of the present invention is to provide a word processorprovided with a control unit for spelling verification and anothercontrol unit for word processing.

Still another object of the present invention is to provide a wordprocessor with improved operability through effective utilization of adictionary of ordinary words and through anticipation of entry of propernouns such as human names.

Still another object of the present invention is to provide a wordprocessor in which the capacity of the text memory is significantlyreduced and operability is improved through effective utilization of adictionary of ordinary words.

Still another object of the present invention is to provide a wordprocessor capable of various operating modes, such as a spelling verifymode for each entered word and a text compression mode by conversion ofeach word into an identification code, according to the purpose of use,through effective utilization of a dictionary of ordinary words.

Still another object of the present invention is to provide a wordprocessor capable of efficiently handling a large amount of textinformation with a limited memory capacity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an external perspective view of an electronic typewriterembodying the present invention;

FIG. 2 is a front view of an operation panel of the electronictypewriter;

FIG. 3 is a block diagram of the electronic typewriter;

FIG. 4 is a functional block diagram of a spelling verify unit SVCU 15shown in FIG. 3;

FIG. 5(a) is a conceptional view showing conversion of key entered wordsinto identification codes;

FIG. 5(b) is a conceptional view showing automatic identification ofproper nouns such as human names;

FIG. 5(c) is a conceptional view showing a process in case of an errorin the key entry;

FIG. 5(d) is a conceptional view showing conversion of text data ofidentification codes ID in a text buffer TB into character code data forprinting;

FIG. 6 is a flow chart showing a process when a slide switch on akeyboard 10 is positioned at manual mode MN;

FIG. 7 is a flow chart showing a process in case the slide switch of thekeyboard 10 is positioned at an automatic verify mode AV;

FIG. 8 is a flow chart showing a process in case the slide switch of thekeyboard 10 is positioned at an automatic verify and conversion modeAVC; and

FIG. 9 is a flow chart showing a process for printing text data storedin the text buffer TB.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now the present invention will be clarified in detail by embodimentsthereof shown in the attached drawings.

FIG. 1 is an external perspective view of an electronic typewriterembodying the present invention, wherein a platen knob 1 is used formanual loading of a typewriting sheet or for fine adjustment of theprinting position in the vertical direction. When pushed inwards, theplaten knob 1 is disengaged from internal coupling with a stepping motorand can be manually rotated. A paper support 2 guides the typewritingsheet and directs the printed texts toward the operator even when a thinpaper is used. A page end indicator 3 is a scale indicating the lengthof paper to the last line of printing, and is vertically adjusted inadvance, as indicated by arrows, by the operator according to the lengthof typewriting sheet, so that the operator can know the length of sheetto the last printing line when the upper end of the sheet reaches themarks on indicator 3. A release lever 4 releases pinch rollers,positioned under the platen, from the platen and is manipulated in casethe position of the typewriting sheet has to be manually corrected. Anoise cover 5, for shielding noises of impact printing, is composed of atransparent resin so that the printed characters can be seen through thecover. Cover 6 can be opened by rotation to the back, for replacing aribbon cartridge or changing a type-font wheel, mounted on a carriage,to another font. The present electronic typewriter provides threeprinting pitches: 10, 12 and 15 characters per inch, and a proportionalspacing in which the printing pitch is variable according to the size ofeach character. A scale 8 has three gradations in 10, 12 and 15characters per inch. A carriage indicator 7 is composed for example ofthree light-emitting diodes or lamps, which are mounted on the carriage,and one of the lamps corresponding to the printing pitch selected by thekeyboard 10 is lit to indicate the position of the carriage on the scale8. The keyboard 10 is composed of a group of character keys 10a forentering and printing characters, and groups of control keys 10b, 10cplaced on both sides.

FIG. 2 is a front view of an operation panel of the electronictypewriter. A PITCH key is used for selecting the number of charactersprinted per inch, and in response to actuations of this key, lamps suchas light-emitting diodes, constituting a display unit L1 are cyclicallylighted in the order of `10`, `12`, `15` and `PS`, wherein the firstthree represent the number of characters per inch, while PS stands forproportional spacing in which the number of characters per inch isvariable according to the characters to be printed. A LINE SPACE keyselects the amount of line feed, the basic unit of which is 1/6 inches,and lamps of a display unit L2 are cyclically lighted as explainedabove, in response to the actuations of this key. A KB SELECT keyselects a third character on a key which represent three characters,such as a key K III, that cannot be selected by SHIFT key alone. AR.M.CONTROL key selects the function of the typewriter at the right-endmargin, and a display unit L4 cyclically shows JUST, AUTO or OFF inresponse to the actuations of this key. JUST indicates the a mode ofright-end justification or alignment, while AUTO indicates a mode ofautomatic line feed, and OFF indicates absence of instruction. An OPCONTROL key selects the printing mode of the electronic typewriter. Amode indicator lamp C, W, L or STORE is lighted in response to theactuation of this key. C indicates printing for every character; Windicates printing for every word; L indicates printing for every line;and STORE indicates storage into a text buffer TB, in which case theprinting is effected in the line printing mode L. A MEMORY key is usedfor processing a text and initiates the function of memory. A marginrelease key MARREL releases a margin stop state in which key entry isprohibited, and is also used for releasing in case of a spellingverification error in a word entry to be explained later. A relocationkey RELOC is used for repeated spelling verification for a correctedword. A lever switch SSW selects one of three operating modes of thepresent embodiment. When it is positioned at a manual mode MN, thespelling of a word entered immediately before is verified in response tothe actuation of a verify key VER. When it is positioned at an automaticverification mode AV, the spelling of a word is automatically verifiedafter it is entered, when the operator actuates the SPACE key. In thesetwo modes, if storage into the internal text buffer is selected in theSTORE mode, the character codes of the entered word are stored in thetext buffer TB without change. On the other hand, when the lever switchis positioned at an automatic conversion mode AVC, the spelling of aword is automatically verified at the entry of each word, and, at thesame time, the character codes of the word is converted into a wordidentification code ID. In this mode, if the STORE mode is selected, theconverted identification code ID is stored in the text buffer TB.

FIG. 3 is a block diagram of the electronic typewriter, in which thesame components as those in FIG. 1 are represented by same numbers andwill be omitted from the following explanation.

In FIG. 3 there are provided a central processing unit (CPU) 11 forperforming the main control of the electronic typewriter; a read-onlymemory (ROM) 12 storing the programs, shown in FIGS. 6 to 9, to beexecuted by the CPU 11; a random access memory (RAM) 13 for temporarilystoring text data entered by the keys and other data required forcontrolling the typewriter; a printer unit 14 for printing the textdata; a spelling verification unit (SVCU) 15 for verifying the spellingof the key entered words and performing conversion between the charactercodes and the word identification code; and an internal bus line 16 forconnecting the above-mentioned various units to the CPU 11.

It is also possible to communicate data with another electronictypewriter or the like by connecting an unrepresented serial interfaceto the internal bus line 16.

The spelling verification unit (SVCU) 15 is provided, for achievingcomplex functions with a simple structure, with a central processingunit (CPU) 152 for main control; a read-only memory (ROM) 153 storingcontrol programs, shown in a part of FIGS. 6 to 9, of CPU 152; a randomaccess memory (RAM) 154; a dictionary ROM 155 storing the spellings of avery large number of words as a table; an internal bus line 156 forconnecting the above-mentioned units with the CPU 152; and an interface151 for connecting the entire SVCU 15 to the internal bus line 16 of thetypewriter.

FIG. 4 is a functional block diagram showing the functions of thespelling verification unit (SVCU) 15 shown in FIG. 3. In FIG. 4 there isshown a spelling verification and conversion control unit (SVCC) 157which is composed of the CPU 152 and ROM 153 shown in FIG. 3, and whichperforms control for the spelling verification on the key entered wordsaccording to key entered data and other various instruction datasupplied from the electronic typewriter through the interface 151,control for conversion from entered words into word identification codesID for forming text data with such identification codes in the textbuffer TB, and control for inverse conversion from the identificationcodes ID read from the text buffer TB into the character codes forprinting. For achieving such control functions, the RAM 154 is providedwith a character counter CC for counting the number of key-enteredcharacter data supplied from the electronic typewriter, a word buffer WBfor storing the spelling, or the character code data, of a word, a codebuffer IDB for storing the word identification codes ID, and a flagbuffer IDFB for storing the category of the word. FIG. 4 also shows anexample of the dictionary memory 155. As shown in FIG. 4, data for eachword consists of the combination of a spelling part SP, a wordidentification code ID, and an identification flag IDF representing acategory code attached to each word, and such data for plural words arestored as a table. Consequently the SVCC 157 can search dictionarymemory 155 by the spelling part SP or by the word identification codeID.

In this manner high-speed control can be achieved by the use of twocontrol units for spelling verification and for word processing of theentire apparatus. Though the present embodiment is explained withspelling verification in the English language, the same principle can beapplied to Japanese, German, French or any other language.

The apparatus of this kind is principally used for verifying thespelling of the key-entered data, and the apparatus of the presentembodiment is for this purpose provided with the above-mentioneddictionary memory 155. However, one of the features of the presentembodiment is to enable efficient word processing, fully utilizing suchdictionary memory. This feature will be further explained in thefollowing explanation.

FIGS. 5(a)-(d) illustrate the function of the present embodiment. FIG.5(a) shows the conversion of a key-entered word into a wordidentification code ID. In response to entries of the character keys ofthe keyboard 10, corresponding data are supplied, according to therespective purpose of processing, to a line buffer LB of the RAM 13, adisplay buffer DB of the display unit 9, and a word buffer WB of theSVCU 15. The line buffer LB is used for assembling the data of one line,while the display buffer DB is used for displaying. 20 characters, andthe word buffer WB is used for extracting a word for search in thedictionary or for spelling verification. The use of such word buffer WBfor spelling verification independent from the line buffer LB and textbuffer TB allows high-speed and independent word processing and spellingverification. In a mode of the present embodiment, a word is detected bythe actuation of the SPACE key. Thus, in case a word "An" followed bythe SPACE key is entered, the character counter CC counts the number ofcharacters (2)+1 of the word, and the word buffer WB stores thespelling, or character codes, of the word. The SVCC 157 makes a searchwith the character code data in the dictionary memory 155, and acoinciding word "An" is found in the spelling part SP shown in FIG. 4.Thus a corresponding word identification code ID=0023H (H stands forhexadecimal) is stored in the buffer IDB while the category code IDF=Ais stored in the flag buffer IDFB. The code "A" indicates the presenceof the searched word in the dictionary, meaning that the identificationcode 0023H in the buffer IDB is effective. The CPU 11 of the electronictypewriter transfers the content of buffer IDB to the text buffer TB,and, the entered character data can therefore be stored into shorterword identification codes. Similar procedures are conducted for theensuing words "electronic (+SPACE)" and "thermometer (+SPACE)". It is tobe noted that the original key-entered data of 26 characters or 26 bytesare reduced to 12 digits or 6 bytes when stored in the text buffer TB.

FIG. 5(b) shows automatic identification of proper nouns such as humannames or symbols and marks. In general, human names cannot be adapted tosearch in a dictionary. In the present embodiment, therefore, uselessspelling verification is omitted for the entry of human names or thelike. For this purpose it is required to anticipate the entry of a humanname, since, otherwise, the human name may be identified afterunnecessary search in the dictionary. In the present embodiment,therefore, it is rendered possible to identify certain abbreviationswhich usually precede human names. For example, if a word "Mr." isidentified in the dictionary memory 155 shown in FIG. 4, the succeedingword should be a human name. Thus, in order to achieve theabove-explained control, a category code C is given to theidentification flag IDF of the word "Mr." in the present embodiment. Asimilar process can be conveniently applied by giving the same categorycode C to similar words such as "Mrs.", "Dr." etc. Also this concept canbe easily applied to words other than proper nouns. Now referring toFIG. 5(b), after the search of the word "Mr." in the dictionary memory,the CPU 11 of the electronic typewriter identifies the identificationflag C in the flag buffer IDFB to automatically exclude the followingword from verification or code conversion. In an operating mode, itbecomes necessary to store text data already converted into the wordidentification codes and unconverted text data, mixedly in the textbuffer TB. Thus, the case of storing unconverted text data such as theabove-explained proper nouns, in the text buffer TB, the CPU 11 attachesa particular mark "*", then inserts the content of the character counterCC in order to indicate the number of characters, and finally stores thecharacter codes of the spelling through the buffer IDB.

FIG. 5(c) shows the procedure in case of an erroneous key entry. In theillustrated example, the first search in the dictionary provides anegative result since the word "stabirization" is misspelled and letter"r" should be "1". This result is indicated by IDF =F, wherein categoryF is given by the SVCC 157 which has detected the absence of the subjectword in the dictionary. In response the CPU 11 of the electronictypewriter inverts the display of the word in the display buffer DB, andapplies a temporary margin stop to the keyboard 10, thus forbidding thefurther movement of the cursor to the right, thus drawing attention ofthe operator. For this purpose there may also be employed flashing ofthe display or other suitable method. In this state the operator canreturn the cursor to the left, and is therefore capable of returning thecursor to the position of "r" and correcting it to "1". After thecorrection the operator actuates the RELOC key, whereby the search inthe dictionary is effected again and a word identification code ID=4C35and a category code IDF=A are respectively transferred to the buffersIDB, IDFB. At this point the CPU 11 transfers the content of IDB to thetext buffer TB.

FIG. 5(d) shows a state of converting text data consisting of the wordidentification codes ID in the text buffer TB into character code datafor printing. At first the word identification codes ID of the textbuffer TB are transferred to the code. buffer IDB in the RAM 154 of theSVCC. Then the CPU 11 supplies the SVCC 157 with an instruction forreverse conversion, whereby the SVCC 157 searches the dictionary memory155 with a code ID=4C35 and stores a corresponding word "stabilization"in the word buffer WB. Subsequently the CPU 11 transfers these charactercodes to the print buffer PB for printing the characters in succession.

Manual mode!

As explained above, the apparatus of the present embodiment is providedwith converting means for converting from character data toidentification code data and converting means for converting fromidentification code data into character data, and is thus capable ofstoring text data in the text buffer TB in the form of shorter wordidentification codes ID. It is therefore rendered possible tosignificantly reduce the size of the text buffer, or to store a largeramount of text data in the text buffer of a given capacity. Alsocommunication with another-electronic typewriter or the like can be madevery efficiently, since the text of a page can be transmitted veryquickly because of the shorter length of data.

FIGS. 6 to 8 are flow charts showing the control procedure of the CPU 11in three operating modes of the present embodiment, wherein FIG. 6 showsthe control procedure in case the lever switch on the keyboard. 10 ispositioned at the manual mode MN. A manual verify (MV) program isselected and activated in the ROM 12 by a mode selection signal from thekeyboard 10 shown in FIG. 3. In this operating mode, the spellingverification is not conducted by the actuation of the SPACE key, but isconducted, in response to the actuation of the VER key, for animmediately preceding word. This operating mode allows key entries athigh speed and is practically convenient since the verification can beselected only when needed, for example when the operator cannot beconfident with the key entry operation. The VER key also has a functionof forcedly dividing a word, and can therefore be utilized for cutting aword at an arbitrary position.

Referring to FIG. 6, a step M1 awaits a key entry. A subsequent step M2identifies if the VER key has been actuated. If not, the programproceeds to a step M3 for a key input process, for example transferringthe entered character code to the line buffer LB, display buffer DB andword buffer WB, or executing insertion, deletion, cursor movement etc.in response to a word processing key input. In case the VER key isactuated, the program proceeds to a step M4 to supply the SVCC157 with a"start SVC(1)" instruction, and a step M5 awaits the completion of theprocess in the SVCC 157. The process executed by the CPU 152 of the SVCCis represented by steps S1 and S2. The step S1 performs a search of thecontent of the word buffer WB in the dictionary memory 155, and the stepS2 transfers a corresponding identification flag IDF to the flag bufferIDFB. When a step M5 identifies that the SVCC is no longer busy, a stepM6 inspects whether the flag buffer IDFB contains a flag F. If thecontent is not F, indicating the presence of the searched word, theprogram proceeds to a step M7 for releasing an instruction of "SVCresetting", whereby the CPU 152 of the SVCC executes steps S3 and S4 toresets the character counter CC and the word buffer WB. Subsequently, ina step M8, the CPU 11 of the electronic typewriter executes a marginrelease to enable the movement of the cursor, and the program returns tothe step Ml for awaiting the key entry.

On the other hand, if the step M6 identifies the content of the flagbuffer IDFB as F, indicating the absence of the searched word, theprogram proceeds to a step M9 to apply a margin step, thus preventingthe cursor from further advancement. However the cursor can be reversedfor certain processes. A succeeding step M10 identifies if there hasbeen actuated the margin release key MAR REL. The actuation of themargin release key indicates that the program should proceed to theentry of the next word, without being bothered with the spelling of thesearched word. Thus the cursor movement is enabled and the programproceeds to the step M7. On the other hand, if margin release key MARREL has not been actuated, a step M11 identifies whether the relocationkey RELOC has been actuated. If the relocation key has been actuated,the dictionary memory is searched again. This procedure corresponds tothe case of re-verification after a correction in the spelling. If therelocation key RELOC has not been actuated either, a step M12 executes akey input process, such as a cursor movement, a character insertion ordeletion or conversion for correcting the erroneous spelling. Asexplained in the foregoing, this operating mode allows the operator toverify the spelling at an arbitrary timing.

Automatic verification mode!

FIG. 7 is a flow chart showing the process when the lever switch of thekeyboard 10 is positioned at an automatic verify mode AV. An automaticverify program (AV) is selected in the ROM 12 by a mode selection signalfrom the keyboard 10 shown in FIG. 3. In this operating mode, thespelling verification is automatically executed for each word,identified by the actuation of the SPACE key. Also in this operatingmode, the spelling verification is conducted, in response to theactuation of the verification key VER by the operator, for a wordentered immediately before. In this case the VER key has the function offorcedly dividing a word independently from the SPACE key, and can beconveniently used for dividing a word at an arbitrary position.

Reference is now made to FIG. 7, in which the steps as those in FIG. 6are represented by the same symbols and will be omitted from thefollowing explanation. As explained before, the spelling verification inthe automatic verify mode AV is conducted for every word, which isidentified by detecting the actuation of the SPACE key. Thus, a step A1identifies if the SPACE key has been actuated, and, if not, the programreturns to the step M1 for awaiting the next key entry. On the otherhand, if the SPACE key has been actuated, the program proceeds to a stepA2 for identifying whether the flag buffer IDFB contains a flag C. If aflag C is present, indicating that the SVCC 157 has identified theimmediately preceding word as a determined abbreviation preceding forexample a human name, the program proceeds to a step A3 which returnsthe content of the flag buffer IDFB to A without any spellingverification, since the human name immediately following theabbreviation is not suitable for search in the dictionary. Howevercertain proper nouns, for example names of places such as Tokyo, can beprocessed in the same manner as ordinary words. If the flag C is absentin the step A2, indicating that the entered word is an ordinary word,the program proceeds to a step M4 to thereafter follow the same flow asexplained in relation to FIG. 6.

The data transfer to the text buffer TB in the present operating mode iseffected by accumulating character code data of a line in the linebuffer LB.

Though not illustrated, it is also possible to dispense with thespelling verification for any word with a certain number of charactersor less, since the errors in spelling are quite few in the shorter wordssuch as "an", "I", "he" etc. Such control can be realized with acriterion that the number of characters does not exceed a certain value.

Automatic verification and conversion mode!

FIG. 8 is a flow chart showing the process when the lever switch of thekeyboard 10 is positioned at the automatic verification and conversionmode AVC. In this mode, an AVC program is selected in the ROM 12 andactivated by a mode selection signal from the keyboard 10 shown in FIG.3. Referring to FIG. 8, the same steps as those in FIGS. 6 and 7 arerepresented by the same symbols and will be omitted from the followingdescription. In this operating mode, the spelling verification isautomatically effected for any word, which is identified by theactuation of the SPACE key, and the word confirmed by verification isconverted into a corresponding identification code ID and stored in thetext buffer TB. Also as in the foregoing modes, in response to theactuation of the VER key by the operator, characters entered immediatelybefore are considered as a word and the spelling verification iseffected for said word.

One of the features of this operating mode is that, in case a step A2identifies an immediately preceding word as a certain abbreviation whichprecedes a human name, the program proceeds to a step Cl to transfer asymbol `*`, the content of the character counter CC and the content ofthe word buffer WB to the text buffer TB. Since a human name cannot beconverted into an identification code, it is stored in the text bufferin the form of character codes. The mark `*`, and the number ofcharacters are attached in order to facilitate later recognition by theCPU 11. As explained before, popular names of places or the like can beincorporated in the dictionary memory 155 since they can be searched inthe dictionary. Also the dictionary memory 155 may partly contain arandom access memory for registering suitable data by the operator.

Another feature of this operating mode is that, when a step M6identifies that the flag buffer does not contain F, meaning that thesearched word has been found in the dictionary, the program proceeds toa step C2 to transfer the word identification code ID in the buffer IDBto the text buffer TB. For this purpose, a step Ti executed by the CPU152 of the SVCC transfers the identification code ID of the word,confirmed by verification in the dictionary, to the buffer IDB. With theprogress of the key entry process in this manner, the text buffer TBwill contain text data consisting assembled character codes andidentification codes ID obtained by code conversion.

Print model!

FIG. 9 is a flow chart showing the process of printing the text datastored in the text buffer TB. A step P1 reads data of 1 byte from thetext buffer TB. Then a step P2 identifies whether the data consist of aparticular code `*`. If so, the text buffer TB contains data on thenumber of characters and data on the word. Thus a step P3 reads the dataon the number of characters, then a step P4 reads character codes of thenumber and a step P5 transfers the data of the thus read word to theprint buffer PB. The data thus transferred into the print buffer PB areprinted according to another unrepresented program of the electronictypewriter. A step P11 inspects an end code to identify whether theentire text data are processed, and, if not, the program returns to thestep P1. On the other hand, if the entire text data have been processed,the printing routine is terminated.

In case the particular code `*` is not found in the step P2, a step P6reads a succeeding identification code of 1 byte, and a step P7transfers it to the buffer IDB of the SVCU 15. Then a step P8 releasesan instruction `start SVCC(3)`, and a step P9 awaits the completion ofexecution by the SVCC 157. On the other hand, a step U1 executed by theCPU 152 of the SVCC 157 performs a search of the identification code IDin the dictionary, and, upon finding a coinciding code, reads thespelling SP of a corresponding word, and a step U2 transfers thespelling to the word buffer WB. When a step P9 identifies that the SVCCis no longer busy, the CPU 152 of the electronic typewriter transfers,in a step P10, the content of the word buffer WB to the print buffer PB.The content of the word buffer WB can also be transferred to the displaybuffer for display on the display unit 9.

As explained in the foregoing, the present invention not only allows oneto significantly reduce the capacity of text memory but also is easilyadaptable to the word processing of specific or technical fields throughthe use of a dictionary of ordinary words, since the words present inthe dictionary are stored after conversion into word identificationcodes of shorter length while the words not present in the dictionaryare stored in the form of characters.

Also the present invention provides a word processor an improved costperformance, since a dictionary memory can be used in various modes byswitch means according to the purpose of use, such as a spellingverification mode for every entered word, or a compression mode for textinformation by conversion into word identification codes.

Furthermore the present invention allows one to significantly reduce thecapacity of the text memory by converting each key-entered word into ashorter identification code of a determined length for storage in thetext memory, and it is therefore rendered possible to realize a smallerdimension and a lower cost for example in the case of providing aconventional electronic typewriter with a spelling verificationfunction.

Furthermore the present invention allows one to store text informationof a large amount in a memory of a limited capacity, and such storage isadvantageous for data storage in an external memory medium and realizesdata communication with another equipment within a shorter time.

Furthermore the present invention enables one to dramatically improvethe operability of the apparatus, since words not present in thedictionary, particularly proper nouns such as human names, areautomatically distinguished and excluded from the spelling verification.

Furthermore the present invention allows one to significantly reduce thecapacity of the text memory and to improve the operability, even throughthe use of a dictionary containing ordinary words only, since the wordspresent in the dictionary are converted into identification codes of adetermined length and are stored, while the words not present in thedictionary, particularly proper nouns such as human names, areautomatically distinguished and stored in the form of character codes.

It is further rendered possible to provide an apparatus with improvedoperability, through the use of separate control units for the wordprocessing and for the spelling verification, thus exploiting maximumfunctions thereof at a high speed.

What is claimed is:
 1. A document processing apparatus comprising:keyinput means for inputting character information, separation informationfor indicating the end of a word formed by the character information,and instruction information for producing a spelling verificationinstruction; dictionary means for checking the spelling of a word formedby the character information input by said key input means; selectionmeans for selecting one of a plurality of spell checking modes includingfirst and second spell checking modes; and control means for, (1) if thefirst spell checking mode has been selected by said selection means,controlling, in response to the separation information being input bysaid key input means, said dictionary means to check the spelling of aword formed by the character information input immediately before theseparation information, and (2) if the second spell checking mode hasbeen selected by said selection means, controlling, in response to theinstruction information being input by said key input means, saiddictionary means to check the spelling of a word formed by the characterinformation input immediately before the instruction information.
 2. Anapparatus according to claim 1, wherein said input means comprises akeyboard.
 3. An apparatus according to claim 1, further comprising printmeans for printing data based on the input document information.
 4. Anapparatus according to claim 1, wherein said selection means comprises aselection switch.
 5. An apparatus according to claim 1, wherein thespecific information comprises a spelling verification code and thepartition information comprises a space key code.
 6. An apparatusaccording to claim 1, wherein if a third one of the plurality of spellchecking modes has been selected by said selection means, said controlmeans determines, as one word, the input document information aspartitioned by partition information and next partition informationinput by said input means, controls said dictionary means to check thespelling of the one word, converts a code of the one word into acorresponding word identification code, and stores the wordidentification code in a memory.
 7. A computer usable memory mediumhaving computer readable program code means embodied therein forinstructing a word processor to perform a spell checking operation, saidcomputer readable program code means comprising:first means for causingthe word processor to input character information, separationinformation for indicating the end of a word formed by the characterinformation, and instruction information for producing a spellingverification instruction in response to a key input operation of keyinput means; second means for causing the word processor to check thespelling of a word formed by the character information input by the keyinput means with dictionary means; third means for causing the wordprocessor to select one of a plurality of spell checking modes includingfirst and second spell checking modes; and fourth means for causing theword processor, (1) if the first spell checking mode has been selected,to control, in response to the separation information being input by thekey input means, the dictionary means to check the spelling of a wordformed by the character information input immediately before theseparation information, and (2) if the second spell checking mode hasbeen selected, to control, in response to the instruction informationbeing input by the key input means, the dictionary means to check thespelling of a word formed by the character information input immediatelybefore the instruction information.
 8. A memory medium according toclaim 7, wherein said first means permits a keyboard to input documentinformation and a spelling verification instruction in response to a keyinput operation.
 9. A memory medium according to claim 7, wherein saidcomputer readable program code means further comprises means forinstructing print means to print data based on the input documentinformation.
 10. A memory medium according to claim 7, wherein saidthird means causes the word processor to select one of the plurality ofspell checking modes in response to activation of a selection switch ofselection means.
 11. A memory medium according to claim 7, wherein saidfourth means causes the word processor, if a third one of the pluralityof spell checking modes has been selected, to determine, as one word,the input document information as partitioned by partition informationand next partition information input by input means, to check thespelling of the one word, to convert a code of the one word into acorresponding word identification code, and to store the wordidentification code in a memory.
 12. A document processing methodcomprising the steps of:inputting character information, separationinformation for indicating the end of a word formed by the characterinformation, and instruction information for producing a spellingverification instruction in response to a key input operation of keyinput means; checking the spelling of a word formed by the characterinformation input by said inputting step with dictionary means;selecting one of a plurality of spell checking modes including first andsecond spell checking modes; and controlling, in response to theseparation information input by the key input means in said inputtingstep, the dictionary means to check the spelling of a word formed by thecharacter information input immediately before the separationinformation if the first spell checking mode has been selected by saidselecting step; and controlling, in response to the instructioninformation being input by the key input means in said inputting step,the dictionary means to check the spelling of a word formed by thecharacter information input immediately before the instructioninformation if the second spell checking mode has been selected by saidselecting step.
 13. A method according to claim 12, wherein saidinputting step is performed with a keyboard.
 14. A method according toclaim 12, further comprising the step of printing data based on theinput document information.
 15. A method according to claim 12, whereinsaid selection step is performed by operating a selection switch.
 16. Amethod according to claim 12, wherein if a third one of the plurality ofspell checking modes has been selected by said selecting step, saidmethod further comprises the steps of determining, as one word, theinput document information as partitioned by partition information andnext partition information input by said inputting step, checking thespelling of the one word, converting a code of the one word into acorresponding word identification code, and storing the wordidentification code in a memory.